hello all
my name is kevin and a owner of a 04 f150 5.4
i am new to this site and wish to learn all i can
about this truck. i have recently encountered a problem
with it.it started out by idling really rough and then cutting off
like you turned the key off.then the next day it shut off 3 times in about
30 minutes.then the engine light came on and the idle was no longer rough
instead it was high.i am mechanically able to do the work so i took it to a mechanic freind of mine to put it on the computer to pull the code off it and it kept comming up unable to communicate with vehicle.we tried several times tyo no avail.so i took it somewhere else to try another scanner same thing. so i called the local dealers service department(freinds there also)to get advice.he told me to check all fuses and check to see if there was power at the 16 pin conector and there was so tried to scan again no luck!
can anyone lead me in the right direction from here ? even though i have contacts at the dealer i still dont want to have to pay there outrgeous prices
any help will be greatly appreciated
kevin

 

Your friend is probably using a scan tool that doesn't support CAN networks. Tote it down to Autozone and get them to check the codes for free, and don't listen to whatever advice they give you. Get the codes and post 'em here.

 

Hi & welcome.

Your issue is likely that the OBDII code readers are not capable of dealing with the 04+ CAN ( controller area network) PCM protocols in these newer trucks.

You will need to find a place with a compatible scanner ( or - the dealer).

Got an AutoZone nearby? - they can do it for free - provided their unit is compatible.

Pull the code & post back here.

Good luck.

bubba

EDIT - dang Q beat me to it, LOL

 

thanks guys i was kinda thinking the same thing i will go to autozone in the morning and post the results

kevin

 

well fellas
you were correct autozone had no problem pulling codes!here they are
p0171 bank 1 to lean
p0174 bank 2 to lean

it also lists possible causes
maf sensor
o2 sensor
ignition mis fire
fuel injector problem
engine mechanical condition

i suspect the maf sensor let me know what you guys think

thanks kevin

 

Hi.

Here's what a quickie search pulled up - lots of threads on this issue:

https://www.f150online.com/forums/sh...t=p0171+bank+1

Good luck.

bubba

 

I like this one -

https://www.f150online.com/forums/sh...d.php?t=296974

 

There's a vacuum hose on the lower driver's side of the intake manifold on a 5.4 3V that rots out often, causing a big vacuum leak. You'll have to pull the intake manifold to see it, or if you've got really long arms and a really long pair of needle nose pliers, you can grab hold of it from underneath the truck. Listen for a vacuum leak near the brake booster/lower driver's side of the intake.

 

hello

i have cleaned the maf sensor wasn't really dirty and checked visable vaccum lines no cracks or holes is removing the intake manifold as easy as it looks or am i missing something important also if you have any pics of the area where that line is can you post them so i can get an idea where to look. thanks kevin

 

You need to make sure that this hose is your problem before needlessly pulling off the intake manifold. Again, listen carefully around the master cylinder/intake manifold area. Pull and wiggle on the vacuum hose on the master cylinder to see if you can hear any air hissing, or if you can make the truck run strange by pulling on this hose. Try spraying some carb cleaner around that area, see if the engine races or the idle smooths out.

 

If you have one of those little tanks of propane for sweating copper, you can use that in the area where Quintins talking about as well. That will make her run a little goofy if she gets a wiff of that.

 

Just pull your PCV hose out completely. Inspect the elbows.

95% odds you'll be holding your problem in your hands.

Check the easy and common stuff first.

Steve

 

hi
are we refering to the vaccum line that runs from the little canister next to the master cylinder to the oppisite side valve cover? if so that line is ok no cracks or hoes.i have also done the carb cleaner thing ,sprayed all around lines and intake ,no change in engine also there is a little red line on the passenger side of intake that runs along the fuel rail it has what seems to be a round plastic plug on it is this supposed to be like this or has the top broke off of somthing that i can;t see?

 

No.

Locate the PCV valve on the passenger side valve cover. Follow the hose to the back of the intake. Inspect every elbow on that hose. Hope you have long arms and small hands.

Steve

 

steve
i must be missing somthing here! there is no vacum coming off passenger side valve cover running to back of intake only one hose running from a metal fitting to top of intake and its a hard plastic line with no elbows also there is one on the other side coming from front of valve cover to the top of the throttle body . this is getting very confusing now!!!!!
kevin